On the south side of the barn, I boxed in a tunnel ventilation fan on a frame. I hung it on a rail, making it into a sliding door. I can unplug it and open the door to let the cattle in and out.

In the wall in front of each of the mangers, I placed a 50-inch fan facing south. By leaving the north door open, a breeze is created. The ventilation fan is held in place by the suction it creates.

Benjie Shirk, Wisconsin